MALAYSIAN JOURNAL OF CHEMISTRY (MJChem)

MJChem is double-blind peer reviewed journal published by the Malaysian Institute of Chemistry (Institut Kimia Malaysia) E-ISSN: 2550-1658

Lawn Grass as A Sustainable Adsorbent for Nickel(II) Removal

Chia-Chay Tay
Universiti Teknologi MARA
Alice Daniel
Universitat Magdeburg
Soon-Kong Yong
Universiti Teknologi MARA
Suhaimi Abdul- Talib
Universiti Teknologi MARA

DOI: https://doi.org/10.55373/mjchem.v24i2.29

Keywords: Adsorbent; lawn grass; nickel(II); sustainable; waste to resource

Abstract

Lawn grass is a waste that has the potential to be converted into an adsorbent to remove nickel(II) from aqueous solution. The methodology includes preparation of the adsorbent, performance of nickel(II) adsorption, evaluation of existing models and characterization of absorbent by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDX). The results showed the optimum adsorbent amount, initial pH and time were 0.35 g, 5.62 + 0.38 and 30 minutes, respectively. Inductively coupled plasma - optical emission spectroscopy (ICP-OES) results suggested an ion exchange mechanism through a displacement of alkaline and alkaline earth metal ions by nickel(II) ions. The results were a better fit to the Langmuir isotherm than Freundlich, with a maximum uptake of 42.02 mg/g. The calculated Langmuir maximum uptake value was comparable to other adsorbents. The adsorption performance corresponded excellently with the pseudo-second-order kinetic model compared to the pseudo-first-order kinetic model. These findings indicated that adsorption of nickel(II) using lawn grass involved a homogeneous monolayer surface, with chemisorption as the rate-limiting step. Thermodynamic evaluation revealed that the adsorption process of nickel(II) by lawn grass is non- spontaneous with weak reversible bonding and endothermic reaction. SEM results showed that the irregular and highly porous surface of lawn grass became smooth after the adsorption of nickel(II). The EDX results supported the ICP analysis which suggested an ion exchange mechanism was involved.

PDF

Published 15 June 2022


Issue Vol 24 No 2 (2022): Malaysian Journal of Chemistry

Section